At the present time the painting or decorating of a woven or non-woven fabric sheet using a marking device is a widespread and popular home hobby. For example, a lightweight cloth fabric is stretched on a hoop assembly. The fabric is painted upon using a ball point marking device having a colored fluid paint. The fabric sheet may have a pattern printed on its surface outlining the areas to be colored by the various colored marking devices.
The ball point marking device comprises a tip holding, at its end, a metal ball and a coil spring loading the ball. The tip is connected to a paint reservoir, which may be a solid or a collapsible tube. The paint is much thicker than fountain pen ink and is placed under pressure, for example, by squeezing the collapsible tube or by a rubber-like bulb which, when compressed, forces air into the tube. The paint consists of pigment dispersed in a mineral spirit vehicle.
There are a number of problems with the presently available marking device paint dispensing systems. The fluid paint may separate in the tube before it is used. If the paint becomes separated, part of the paint may be thin, so that it spreads and ruins the fabric and, in addition, the paint will not provide a uniform color. The marking devices, consequently, have a limited "shelf-life", i.e., the paint in such devices will separate within a few years. Consequently, it may happen that the seller of the marking devices may, inadvertently, sell tubes with separated paint to his customers, since such tubes with separated paint are not distinguishable in appearance from fresh tubes; the users may find they have to replace one or more colors before using the contents of the tube since the remaining paint may have separated; and the manufacturer of the marking devices may be plagued with returned devices and dissatisfied customers. In addition, the paint may dry or separate at the tip, i.e., at the ball, causing the ball to jam or stick.
The paint, since it is based on mineral spirits, has a distinctive odor and has become increasingly expensive. In addition, over time, the pigment may partially settle so that the paint is less pigmented when use is started and more heavily pigmented after using the marking device for a time, providing uneven color. The paint is relatively messy, hard to remove from fingers and, in a few cases, may be mistaken for food by very young children and eaten.
One type of house paint, using water as its base, is called an "emulsion" paint. However, such paint is not an emulsion in the sense of globules, one fluid phase dispersed into another fluid phase, but rather consists of solid resin particles dispersed in a water base.